A table saw is a power tool used to cut a workpiece to a desired size or shape. The workpiece may be formed from a variety of materials, including wood, laminates, plastic, metal, combinations thereof, and the like. A table saw includes a work surface, or table, and a circular blade extending up through the table. A person uses a table saw by holding a workpiece on the table and feeding it past the spinning blade to make a cut in the workpiece.
The table saw is an essential piece of woodworking equipment and has been so for decades. Despite the long-time and widespread use of table saws, the blade of a table saw presents a considerable risk of injury to a user of the saw. If the user accidentally places the user's hand in the path of the blade, or if the user's hand slips or is otherwise thrust into contact with the blade, then the user could receive a serious injury or amputation. Accidents also happen because of what is called kickback. Kickback may occur when a workpiece contacts the downstream edge of the blade as it is being cut. The blade then propels the workpiece back toward the user at a high velocity. When this happens, the user's hand may be carried into the blade because of the sudden and unexpected movement of the workpiece. Additionally, the user may be injured when contacted by the workpiece that is propelled toward the user by the spinning blade.
Safety systems or features may be incorporated into table saws to reduce the risk of injury. Probably the most common safety feature is a guard that physically blocks an operator from making contact with the blade. In many cases, guards effectively reduce the risk of injury; however, there are many instances where the nature of the operations to be performed precludes using a guard that completely blocks access to the blade. In still other instances, the guard is not present on the table saw due to a user deciding not to use the guard regardless of the cutting operation being performed. In many of these instances, this choice may have been predicated upon conventional guards being perceived by the user as being bulky, inconvenient to use, and/or obstructing the user's view of the workpiece as it is cut by the spinning blade of the table saw.
Another safety device that is sometimes incorporated into table saws is a spreader, or splitter. A splitter is a flat plate, similar to a riving knife, but typically extending above the top-to-bottom cutting capacity of the blade so that a blade guard can be mounted thereto. Some splitters and/or guards include anti-kickback devices that are configured to restrict a workpiece from being propelled back toward a user by the spinning blade. An illustrative example of a conventional anti-kickback device is an anti-kickback pawl, which is a toothed pawl that is positioned to oppose a workpiece being thrown back toward a user.
Other safety systems have been developed to detect when a human body contacts a predetermined portion of a machine, such as detecting when a user's hand touches the moving blade of a saw. When that contact is detected, the safety systems react to minimize injury. These systems may be used in conjunction with table saw attachments such as blade guards, riving knives, splitters and anti-kickback pawls.
The present document discloses improved table saw guards, table saw attachments, and table saws that include the same.